Magnetically coded card structure

ABSTRACT

A monolithic card is formed of three plastic sheets bonded together, wherein the center sheet has a plurality of holes, each filled with a magnetic disc adapted to be axially poled. The center sheet is punched at one station, then located at a second station beneath a flexible card of magnetic material, and with its holes aligned with respective punches which simultaneously punch discs from the card and force them into holes. The center and outer sheets are stacked, and bonded under heat and pressure. The discs are magnetized with polarities at one card face distributed in a desired pattern.

United States Patent Barney Mar. 21, 1972 MAGNETICALLY CODED CARD STRUCTURE [58] Field of Search... ....235/6l.12; 340/149; 346/74 M [56] References Cited UNITED STATES PATENTS 3,015,087 12/1961 O'Gorman ..340/149 3,465,131 9/1969 Ten Eyck ..235/61.l2 3,465,307 9/1969 Schmidt ..235/61.12

3,117,065 l/l964 Wootten ..235/61.l2 X

3,452,358 6/1969 Zehner 3,154,761 10/1964 OGorman ..340/149 FOREIGN PATENTS OR APPLICATlONS 1,124,205 6/1956 France ..235/61.l2

Primary Examiner-Thomas A. Robinson Attorney-Perry E. Turner [5 7] ABSTRACT A monolithic card is formed of three plastic sheets bonded together, wherein the center sheet has a plurality of holes, each filled with a magnetic disc adapted to be axially poled The center sheet is punched at one station, then located at a second station beneath a flexible card of magnetic material, and with its holes aligned with respective punches which simultaneously punch discs from the card and force them into holes. The center and outer sheets are stacked, and bonded under heat and pressure. The discs are magnetized with polarities at one card face distributed in a desired pattern.

2 Claims, 4 Drawing Figures MAGNETICALLY CODED CARD STRUCTURE CROSS-REFERENCE TO RELATED APPLICATION This application is a division of my application, Validator Apparatus for Magnetic Credit Cards and the Like," Ser. No. 650,483, filed June 30, 1967, now U.S. Pat. No. 3,430,200, issued Feb. 25, 1969.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to magnetic cards for use as credit cards and the like.

2. Description of the Prior Art Magnetic cards as heretofore known have been made of laminations having a center sheet with holes in which very thin metal magnets are located. Such permanent magnets must be individually formed to insure they will be flat when placed in their holes. After these magnet shims are placed in their holes, a stack is made with such center sheet between two outer sheets, and the sheets are bonded together.

Such techniques are unduly time consuming and expensive, and militate against high volume production of credit cards having embedded magnets.

SUMMARY OF THE INVENTION My invention embraces the means and steps for simultaneously forming discs of magnetic material and inserting them in respective holes in a plastic sheet, and for bonding opaque face sheets to said plastic sheet to form a monolithic card with the magnet discs embedded therein.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a flow diagram illustrating the steps of my process for forming a card of my invention;

FIG. 2 is a fragmentary sectional view taken along the lines 22 of the first punch station shown in FIG. 1;

FIG. 3 is a fragmentary sectional view taken along the lines 33 at the second punch station shown in FIG. 1; and

FIG. 4 is an enlarged, fragmentary sectional view of my card as formed by the process illustrated in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT My invention embraces an opaque laminated card of three layers of flexible, nonmagnetic e.g., plastic) material, wherein the center ply is formed with a plurality of rows of closely spaced holes, and wherein respective permanent magnets are located in the holes. Referring to FIG. 1, the plastic sheet 40 that forms the center ply of the card is inserted in a punch, as between a base plate 42 and a plate 44 which supports the plurality of rows of punches 46 each. A movable press plate 48 is operated to actuate the punches 46 and thereby punch corresponding rows of openings through the sheet 40. The punches are of small diameter and close spaced to effect correspondingly small, closely spaced openings, e.g., openings of 0.125 inch diameter, with their centers 0.25 inches apart, and with 0.25 inch spacing between the center of adjacent rows.

As shown in FIG. 2, the base plate 42 has openings 50 disposed below plungers 52 which are supported in housings 54 supported in the upper plate 44, and which are biased upwardly, as by spring biasing indicated at 56.

After the plungers 52 are actuated to punch out the circular openings in the sheet 40, the sheet 40 is moved to a second punch station in which magnetic elements are formed and inserted in such openings. To this end, the second punch station is shown to include a plate 62 that supports a plurality of rows of punches 64, in the manner of the plate 44 and punches 46 previously described. This punch station also includes a base plate 66, but the base plate in this instance is a solid plate. In addition, the second punch station includes a center plate 68 that has a plurality of circular openings 70 (see FIG. 3) aligned with the plungers 72 of the punches 64.

The punched sheet 40 is sandwiched between the base plate 66 and the center plate 68, with the prc-punched openings in the sheet 40 aligned with the openings 70 of the center plate. Also a sheet 74 from which the magnets are to be formed is sandwiched between the upper plate 62 and the middle plate 68. Then the ram is actuated, causing the plate 76 to actuate the plungers 72 of the punches simultaneously, whereupon (see FIG. 3) such plungers in a single movement punch discs 80 from the sheet 74 and carry them through the plate 68 and into the openings in the sheet 40.

I have found that an ideal material for the magnetic sheet 74 is one of magnetic material, such as barium ferrite, in a rubber or plastic base. In cards of my invention, I am able to form magnets of such magnetic rubber of only 0.015 inch thickness and 0.125 inch diameter. Further in this connection, the sheets 40, 74 are of the same thickness, so that the surfaces of the discs 80 are flush with those of the sheet 40.

. The elements 80 are magnetized coaxially, i.e., so the opposite faces of each are of opposite polarities. Further, the elements 80 are initially magnetized in a predetermined master pattern, and coding is thereafter effected by reversing the polarities of selected ones of the elements. The master pattern preferably is one in which certain magnets are poled in one direction and the rest are poled in the opposite direction. As will be seen, the pattern may be symmetrical or random.

The type of material above described for the elements 80 has the characteristic that, once magnetized, the elements are permanent magnets which can be demagnetized, if at all, only with extreme difficulty. However, the polarities of such permanent magnets can readily be reversed. In this connection, each element may be initially magnetized by an electromagnet formed of a C-shaped core that is encircled by a coil (not shown). A strong pulse of current passed through the coil will magnetize the element. After all the elements 80 are thus magnetized, coding is similarly effected, e.g., by placing selected magnets between the ends of the core and passing current in the opposite direction through the coil.

The elements 80 can be magnetized immediately after they are inserted in the sheet 40 as above described. In such case, the surfaces of the sheet 40 and elements 80 are cleaned to remove any dust or other foreign matter. Then a sandwich is formed of the sheet 40 and a pair of outer layers of thin, opaque plastic sheets 82, 84 (see FIG. 1). This sandwich is placed in a press 86 and subjected to a suitable combination of heat and pressure to fuse the sheets and form a monolithic card blank 88 in which the elements 80 are embedded (see FIGS. 1 and 4). The outer sheets 82, 84 (FIG. 1) may be thinner than the sheet 40, e.g., 0.010 inches thick.

The card blank 88 may then be processed to add visible information, e.g., by embossing it with a customers name and account number. In this latter connection, it is preferred to emboss the card 88 on a portion thereof that does not overlie the magnetic inserts 80. Thus, as illustrated in FIG. 1, the card is provided with a sufficient surface portion, adjacent the rows of elements 80, on which the desired information can be embossed.

While I have described the magnetizing of the discs 80 before the sheet 40 is sandwiched between the sheets 82, 84, the magnetizing of the discs may be done after the card blank 88 is completed. As will be appreciated, since the card blank is opaque, the discs 80 are not visible. However, initial magnetization and coding may be carried out with the indexing and coding apparatus and techniques of my copending application entitled Encoder Apparatus for Magnetic Credit Cards and the Like, Ser. No. 676,138, filed Oct. 18, I967, now U.S. Pat. No. 3,471,862, issued Oct. 7, 1969.

By forming a card with such closely spaced magnets, I provide a substantially tamper-proof device. In this connection, assume that such a card is lost, and the finder attempts to change the code, i.e., so that the code conforms to that of his own or anothers card. To carry out such a scheme, it is of course necessary to reverse polarities of a number of the magnets. But to do this requires that the exact center of each magnet be located, and that the requisite field be concentrated only through the individual magnet. Slight misalignment in this operation results in polarity reversals of one of more magnets in addition to that intended. Since the magnets are so small and closely spaced, and cannot be seen, there is little likelihood that one can accurately locate the centers and reverse the polarities of only those magnets that must be changed.

Iclaim: 1. In combination: an opaque card formed of a center layer of nonmagnetic material between two layers of opaque, non-magnetic material, said center layer having a plurality of spaced openings therethrough; respective permanent magnets in said openings, said magnets being of the same thickness as said center layer, said magnets being resilient elements frictionally and resiliently engaging the walls of the openings in which they are located,

each magnet being so poled that its opposite surfaces are of opposite polarities, whereby said magnets are poled along lines perpendicular to the opposite surfaces of said center layer,

the polarities of some of the magnets at each surface of said center layer being north poles and the remainder being south poles, said north and south poles at each surface of said center layer being in a predetermined pattern,

the field of each magnet outside the card surfaces being sufficiently strong to operate a respective magnet responsive device when the card is placed in a stationary position adjacent the device,

and said magnets being characterized in that the polarities thereof at the card faces are not alterable or erasable by an opposite magnet pole brought or moved adjacent thereto.

2. The combination of claim ll, wherein said openings are circular and said magnets are disc magnets. 

1. In combination: an opaque card formed of a center layer of nonmagnetic material between two layers of opaque, non-magnetic material, said center layer having a plurality of spaced openings therethrough; respective permanent magnets in said openings, said magnets being of the same thickness as said center layer, said magnets being resilient elements frictionally and resiliently engaging the walls of the openings in which they are located, each magnet being so poled that its opposite surfaces are of opposite polarities, whereby said magnets are poled along lines perpendicular to the opposite surfaces of said center layer, the polarities of some of the magnets at each surface of said center layer being north poles and the remainder being south poles, said north and south poles at each surface of said center layer being in a predetermined pattern, the field of each magnet outside the card surfaces being sufficiently strong to operate a respective magnet responsive device when the card is placed in a stationary position adjacent the device, and said magnets being characterized in that the polarities thereof at the card faces are not alterable or erasable by an opposite magnet pole brought or moved adjacent thereto.
 2. The combination of claim 1, wherein said openings are circular and said magnets are disc magnets. 